
/**
 * Interface to represent packet extensions. A packet extension is an XML subdocument
 * with a root element name and namespace. Packet extensions are used to provide
 * extended functionality beyond what is in the base XMPP specification. Examples of
 * packet extensions include message events, message properties, and extra presence data.
 * IQ packets cannot contain packet extensions.
 *
 * @see DefaultPacketExtension
 * @see org.jivesoftware.smack.provider.PacketExtensionProvider
 * @author Matt Tucker
 */
class PacketExtension {
public:
	virtual ~PacketExtension() {}
    /**
     * Returns the root element name.
     *
     * @return the element name.
     */
	virtual std::string getElementName() = 0;

    /**
     * Returns the root element XML namespace.
     *
     * @return the namespace.
     */
	virtual std::string getNamespace() = 0;

    /**
     * Returns the XML reppresentation of the PacketExtension.
     *
     * @return the packet extension as XML.
     */
	virtual std::string toXML() = 0;
};
